A type of vacuum cleaner head is known which is simply a substantially planar member with at least four and often eight or more wheels for supporting the planar member above a pool surface. In this type of vacuum cleaner head the wheels are usually secured between projecting spaced flanges on a brass bolt and nut assembly with the bolt, which forms a wheel axle, passing axially through the wheel and through the projecting flanges.
The disadvantage of the latter type of construction is that the nuts and bolts can work loose, and a wheel and the nut and bolt themselves may be lost or have to be retrieved from the bottom of a swimming pool. Furthermore, the nuts and bolts are usually made of solid brass to avoid corrosion thereof and solid brass articles are extremely costly.